Collecting Rainwater for the Garden – is it Right for You?

Here at J&R Pierce Family Farm, I think it’s important to connect my readers with valuable insight from other experts. Today’s post is a guest post brought to you by Samantha Rainwater.

For many gardeners, the occasional rainfall is not a sufficient source of water if they want to keep their plants happy and healthy. 

This leaves most gardeners turning on the hose every few days to provide that extra boost of water required to keep their hard-earned garden looking beautiful and/or producing crops. Ideally, rainfall would provide all the necessary water needed for a garden to thrive, but Mother Nature’s timing doesn’t always work in our favor. 

While the convenience of perfectly timed rainfalls may be tricky to manipulate, collecting rainwater during a rainfall and saving it for future use is absolutely doable. 

Rainwater collection has been used throughout history and has recently started regaining interest among gardeners and environmentalists alike as the benefits are becoming more clearly understood. You don’t have to go all out— even the simplest rainwater collection system can be a worthwhile investment for your garden if you’re not prepared to go all out. 

collecting rainwater for the garden

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The Benefits of Collecting Rainwater for your Garden 

collecting rainwater for the garden
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There are many benefits associated with collecting rainwater for your garden both directly and indirectly. While the most obvious reason may be free water, there are other reasons that include helping our environment. Collecting rainwater for your garden is not only beneficial to the gardener and to the plants, but to the world around us—so why not give it a try!

Should I Collect Rainwater For My Plants? Yes – and Here’s Why

collecting rainwater for the garden
Photo: Unsplash

Regardless of whether your home gets its water from a city utility source or it’s pumped in from a well, odds are it is treated to some degree to ensure it is safe for human consumption. 

While these water treatment systems are put in place to help keep us safe, they are not necessarily in the best interest of your plants. The needs of a human and the needs of a plant, while similar on a primal level, are complexly different, and for plants, natural rainwater is the healthiest option. 

Is Rainwater Good for the Garden? Absolutely.

While city water is generally safe for your garden plants, trace amounts of chlorine and fluoride are often added to these water sources—again, in the interest of human consumption—and plants can be harmed by even low levels of these chemicals. While well water does not have these chemicals added, it is often considered hard water and many homeowners will invest in a water softening system. 

Water run through these systems may have added sodium which can interfere with a plant’s ability to take up water. Well water may also contain excess minerals that may overwhelm or harm your plants depending on the minerals found in your area. 

Potential to Save You Money

Particularly if your home water comes from a city utility source, you will directly pay for any water you use for your plants when you use your water faucet. The best way to avoid using your home water and to cut costs is by collecting rainwater to use instead. The most common way to collect rainwater is with the use of a rain barrel or other container into which the water collected from the roof can be funneled. 

Even those on well water will save money. While many may view well water as a free water source, the homeowner still pays to install and replace the well pump, meaning that the extra strain on your pump may cause it to need to be replaced sooner. To avoid using your well water on your plants, a rainwater collection system can be implemented to reduce strain on the pump system. 

Better for the Environment

In addition to being beneficial to the gardener and to the plants, collecting rainwater for your garden also provides benefits to the environment. When rainwater falls anywhere on your property, it generally ends up moving its way into a waterway of some sort, whether that be a river, pond, sewer system, etc. 

On its way to these outlets, water often runs through pollution such as fertilizers, pesticides, animal waste, road salts, chemicals, and more, collecting them as they pass through. Bringing these pollutants into waterways can be harmful to the health of both humans and aquatic animals. While we cannot completely eliminate runoff pollution, any water captured and collected for watering your garden will be less likely to be a part of the problem.

Another way that collecting rainwater for your garden can be beneficial to the environment is by reducing erosion and flooding. When rainwater collects and pools in areas such as rooftops, the storm water runoff created can cause erosion in certain areas and flooding if the water is not diverted away properly. By collecting some of that water for later use in your garden, you are reducing the potential damage that the collected water may have caused. 

Allows You To Conserve Filtered Water

Whether your home water comes from a city utility source or from a well, the water that comes out of your faucet has more than likely run through a series of filters to be ideal for human consumption. 

Most city utility water has not only been filtered multiple times, but it also has added chemicals and nutrients to benefit us. Making the water safe and ideal for human consumption requires a large amount of resources and money, and this processed water is not an unlimited source. You can help to conserve this water by collecting and using rainwater for your garden—it’s in everyone’s best interest!

While most well water does not have the same filters and added chemicals, there is generally a filtration process that—at minimum—filters out large debris and minerals that would clog up the pipes in your home. Many well water users also have a water softener system that filters and alters the water in addition to other optional filters that are implemented based on water type and situation. 

If you are the homeowner, you are going to want these filters to last as long as possible to avoid replacing them sooner than needed. While watering your garden may not have a huge impact on your filtration systems, using collected rainwater will certainly reduce the strain—especially if you’re an avid gardener!

How to Collect Rainwater

collecting rainwater for the garden
Photo: Unsplash

 In order to use rainwater to your advantage, it obviously needs to be collected for future use. There are a few different ways to go about collecting rainwater which range from simple to complex depending on your level of investment and need for this resource. For further guidelines and information on collecting rainwater, the United States Office of Energy Efficiency & Renewable Energy website has a thorough program you can check out here

Use Rain Barrels to Collect Rainwater

Setting up rain barrels is one of the most common ways to collect rainwater for future use. Rain barrels are designed to hold rain and are usually structured in a way that is convenient for using that water once you are ready to do so. 

A majority of rain barrel systems are set up to funnel rain from your rooftop directly into the barrel. Some systems utilize gutter downspouts while others may have a downspout-like structure of their own. Depending on your water needs, there are a range of rain barrel sizes to choose from; in addition, there are generally options to add linking rain barrels if your need for rainwater increases. 

Rain barrels are ideal for storing water safely without fear of contamination or evaporation. By using rain barrels, you are able to better control the outcome of your water collection because they are fully customizable to your home and needs. 

How to Collect Rainwater Without Gutters – Using Open Containers

Perhaps the most straightforward method of collecting rainwater is to leave open containers on your property to naturally fill when rainfall occurs. These containers can be anything from a handheld bucket to a small pool. 

With this set up, there is no special equipment or process needed to collect rainwater, but the results will not be as fruitful as they would be with a rain barrel or similar system. If you do collect into a large container, such as a pool, you will need a way to transport the water to your garden. The simplest option may be to carry buckets back and forth as needed; a more efficient method may be to create a siphon from the container to the garden for your watering needs.

The primary issue with open collections is that there is no funnel system to bring in as much water as possible—you will only collect the water that falls directly into the mouth of the container. 

Another issue with this set up is that there is nothing protecting your collected water from falling debris, contaminations, or evaporation—unless you cover the mouth after the rainfall. This method may only be practical for those who live in areas that receive heavy rainfall where plenty of rain can naturally fall into the container, and where the garden will not require much extra water outside of those rainfalls. 

Whole Home Systems

If you want to go all-in with your rainwater collection, you can consider installing a professional rainwater collection system that is sure to take care of all of your watering needs. The most complex systems generally have large storage tanks that are contained either underground or in their own small building.

Similar to a rain barrel, these tanks have rainwater funneled into them and are used as holding tanks until the water is needed. Unlike a rain barrel, these systems will have a pump that will bring the water up to a faucet just as a home plumbing system would. These systems can be altered with filters for human consumption as well if you are looking to replace your current home water source. 

These advanced systems can be pricey to install, but they have the potential to save you money if utilized properly. These systems may be particularly helpful to gardeners who have multiple gardens to water or those who grow to supply their business or farmers market. 

Can you Collect Enough Rainwater to Water Your Entire Garden?

collecting rainwater for the garden
Photo: Unsplash

Depending on your geological location, rainwater collection method, and mother nature’s plans, there is usually the potential to collect all the rainwater you could ever need for your garden. For example, if you have a roof that is roughly 1,000 square feet, you can collect as much as 600 gallons of water with a one-inch rainfall. 

If you are collecting your rainwater from a roof into a rain barrel or other holding container, you can calculate your potential rainwater collection in a few easy steps. The first step is to measure the square footage of your roof. The easiest way to do this is to measure the length and width of your root and multiply to get square footage—this may be a rough estimate if your roof is angled. 

Once you have a square footage, you can multiply that number by the amount of rain received in inches—this can usually be found on weather reports or with the use of a home rain level gauge. 

Finally, you can take that number and multiply it by 0.623, which is the quantity of water in gallons that one inch of liquid produces per one square foot. 

X= square footage of roof

Y= inches of rainfall

X  * Y * 0.623 = Potential gallons of water to be collected

For further details on calculating your potential rainwater capture, the University of Arizona’s cooperative extension is a great source. Check it out here.  

And what about collecting rainwater for indoor plants? In most cases, natural rainfall will provide you with everything you need to keep your indoor-grown flowers, fruits, and vegetables perfectly hydrated, too. 

How Long Can You Store Rainwater for Plants?

collecting rainwater for the garden
Photo: Unsplash

In most cases, rainwater can be stored for anywhere between one week – and beyond. Of course, you’ll want to make sure you have a sealed storage system made out of the right materials, and ideally one that can prevent algae growth and mosquitoes from laying their eggs.

If you’re looking for a few good options, check out this rainwater collection system here and this one here. 

Are There Laws Against Collecting Rainwater in the US?

collecting rainwater for the garden
Photo: Unsplash

There are no federal laws that restrict the collection or use of rainwater on an individual level; however, some states have their own laws that you should investigate before investing in a system.

Prior to 2016, some states had strict laws that practically prohibited the collection and use of rainwater. These laws were based on the thought that altering the water patterns could cause changes in weather and future water availability; this has since been proven to be inaccurate and most restrictive laws have been altered. 

Even so, there are some states that limit the amount of rainwater that a household can collect. Another common law requires any collected rainwater to only be used for personal gardening and irrigation, although it is not recommended to use rainwater for direct human consumption anyways. 

Here is a good reference guide to check state laws on collecting rainwater in your state: 

In addition to state laws, it is a good idea to investigate individual city ordinances which may also prohibit certain rainwater collection systems. 

On an even smaller scale, some homeowners associations may prohibit them as well, particularly if they are an eyesore for the neighborhood—but who cares when you’re saving the planet!

While some states limit rainwater collection and use, there are other states that encourage their residents to use rainwater to relieve some of the strain on the city utilities. Some of these states put efforts into educating their residents on the benefits of rainwater collection while others even offer incentive programs for participating in rainwater collection. 

Do you collect rainwater for your garden? Let us know your favorite tips in the comments!

Celebrate Black Artisans and Makers

Samantha Rainwater is a full-time business owner and recent mom who spends her free time writing. Her degree in Biology gives her a background in science, which she likes to apply on her small hobby farm. Writing about her experiences is one of her passions, and she finds joy in sharing her experiences with others. 

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Author: Rebekah PierceI'm a writer and small farm owner, and lover of everything outdoors. I'm hoping to share my passion for farming, gardening, and homesteading with you on my blogging journey.

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